CNS Flashcards
Hallmark of severe brain injury
Loss of sonsciousness for six or more hours
Causes of focal brain injury
Lesions, edema, coup and contrecoup injury (contusions)
EDH
85% arterial (middle meningeal artery) 15% venous / dural sinus 90% due to skull fracture Temporal fossa is the most common location Earliest symptom is HA
SDH
50% due to skull gractures. Mostly due to bridging veins from torque to the brain
Types of SDH
Acute- Develops within 48 hours of injury and is often located at the top of skull (near bridging veins)
Chronic- develops over weeks to months. Causes chronic HA and tenderness at site. Common in alcoholics.
ICH
Associated with MVA and falls
The hemorrhage acts as an expanding mass. Causes compression of brain tissue with edema
Causes of DAI
AXONAL DAMAGE due to shearing, stretching, or tearing of nerve fibers from shaking, acceleration / deceleration injury, inertial injury
Severity depends on the amount of shearing force applied to brain and brainstem
Grades of Concussion
Grade I- confusion, disorientation, and momentary amnesia
Grade II- momentary confusion and retrograde amnesia
Grade III- confusion with anterograde and retrograde amnesia
Classic Cerebral Concussion
Grade IV
Disconnection of the cerebrum from the brainstem and RAS, causing unconsciousness (<6 hours), anterograde and retrograde amnesia, physiologic and neurologic dysfunction (but ANS still intact).
Types of classic concussion
Complicated (focal injury)
Uncomplicated (no focal injury)
Where is our memory forming system located?
The hippocampus
Postconcussive syndrome symptoms and treatment
HA, cognitive impairments, psychologic and somatic complaints, cranial nerve deficits
Treatment- Reassurance and relief of symptoms. Close monitoring for 24 hours to watch for worsening of symptoms.
Location of most spinal cord trauma
Cervical (1,2,4-7)
Thoracic (T1-L2)
These are the most mobile locations of the vertebral column AND where the cord takes up most of the spinal canal. The area is mobile and the cord doesn’t have much space.
Spinal stenosis
Narrowing at the area where the spinal nerve leaves the vertebra. Can cause numbness, pain, or both, similar to hitting your funny bone. The pain is way out of proportion to the injury actually occurring. Difficult to detect by CT and MRI.
Spinal Shock Affects
Lost normal function below level of injury.
Loss of reflexive function (skeletal, bladder, bowerl, sexual, thermal control, and autonomics).
Remember, if you damage the cord, you will lose your sympathetics because they come from T1-L2. PSNS will be unaffected because that is craniosacral outflow.
Neurogenic Shock
LOSS OF SNS
What would happen if you didn’t have any SNS outflow?
- Vasodilation
- Hypotension
- Bradycardia
- Hypothermia
Think about Garmin’s finger story, and how low your BP could go if actual sympathetics were severed.
Autonomic hyperreflexia
Think about the name. Massive, uncompensated cardio response from SNS outflow due to stimulation of sensory receptors below the level of the cord lesion.
Classic Cerebral Concussion
Grade IV
Disconnection of the cerebrum from the brainstem and RAS, causing unconsciousness (<6 hours), anterograde and retrograde amnesia, physiologic and neurologic dysfunction (but ANS still intact).
Types of classic concussion
Complicated (focal injury)
Uncomplicated (no focal injury)
Where is our memory forming system located?
The hippocampus
Postconcussive syndrome symptoms and treatment
HA, cognitive impairments, psychologic and somatic complaints, cranial nerve deficits
Treatment- Reassurance and relief of symptoms. Close monitoring for 24 hours to watch for worsening of symptoms.
Location of most spinal cord trauma
Cervical (1,2,4-7)
Thoracic (T1-L2)
These are the most mobile locations of the vertebral column AND where the cord takes up most of the spinal canal. The area is mobile and the cord doesn’t have much space.
Spinal stenosis
Narrowing at the area where the spinal nerve leaves the vertebra. Can cause numbness, pain, or both, similar to hitting your funny bone. The pain is way out of proportion to the injury actually occurring. Difficult to detect by CT and MRI.
Spinal Shock Affects
Lost normal function below level of injury.
Loss of reflexive function (skeletal, bladder, bowerl, sexual, thermal control, and autonomics).
Remember, if you damage the cord, you will lose your sympathetics because they come from T1-L2. PSNS will be unaffected because that is craniosacral outflow.
Neurogenic Shock
LOSS OF SNS
What would happen if you didn’t have any SNS outflow?
- Vasodilation
- Hypotension
- Bradycardia
- Hypothermia
Think about Garmin’s finger story, and how low your BP could go if actual sympathetics were severed.
Autonomic hyperreflexia
Think about the name. Massive, uncompensated cardio response from SNS outflow due to stimulation of sensory receptors below the level of the cord lesion.